Karlsruhe Institute of Technology, Institute for Applied Biosciences, Department of Microbiology, D-76187 Karlsruhe, Germany.
Annu Rev Microbiol. 2010;64:585-610. doi: 10.1146/annurev.micro.112408.134000.
Light is one of the most important environmental factors for orientation of almost all organisms on Earth. Whereas light sensing is of crucial importance in plants to optimize light-dependent energy conservation, in nonphotosynthetic organisms, the synchronization of biological clocks to the length of a day is an important function. Filamentous fungi may use the light signal as an indicator for the exposure of hyphae to air and adapt their physiology to this situation or induce morphogenetic pathways. Although a yes/no decision appears to be sufficient for the light-sensing function in fungi, most species apply a number of different, wavelength-specific receptors. The core of all receptor types is a chromophore, a low-molecular-weight organic molecule, such as flavin, retinal, or linear tetrapyrrols for blue-, green-, or red-light sensing, respectively. Whereas the blue-light response in fungi is one of the best-studied light responses, all other light-sensing mechanisms are less well studied or largely unknown. The discovery of phytochrome in bacteria and fungi in recent years not only advanced the scientific field significantly, but also had great impact on our view of the evolution of phytochrome-like photoreceptors.
光是地球上几乎所有生物定向的最重要环境因素之一。虽然在植物中，光感应对于优化依赖光的能量保存至关重要，但在非光合生物中，生物钟与一天长度的同步是一个重要功能。丝状真菌可能将光信号用作菌丝暴露于空气中的指示，并使它们的生理学适应这种情况或诱导形态发生途径。尽管对于真菌中的光感应功能，一个是/否的决定似乎就足够了，但大多数物种都应用了许多不同的、波长特异性的受体。所有受体类型的核心都是生色团，一种低分子量有机分子，例如黄素、视黄醛或线性四吡咯，分别用于蓝、绿或红光感应。虽然真菌中的蓝光反应是研究最充分的光反应之一，但所有其他光感应机制的研究都较少或几乎未知。近年来在细菌和真菌中发现的光敏色素不仅极大地推动了科学领域的发展，而且对我们对类光敏色素光受体进化的看法也产生了重大影响。
